The present invention relates generally to the improvement of flow characteristics of materials from storage bins and more particularly to a device which may be suspended within such a storage bin to direct the material flow and on occasion to agitate the material so as to provide a uniform material flow from the bin.
It is well known that in draining materials from storage containers by gravity flow, irregularities in that flow within the container may occur. For example, in hopper bins used to store feed for cattle or poultry or other grain-like materials, flow variations due to variations in particle size may result in a lack of uniformity of the material exiting the bin. Also, material may adhere to or build up on side wall portions of the bin resulting in a funneling type flow or the creation of voids within the material, often referred to as arching or bridging, as well as numerous other flow irregularities. In such hoppers where material is added to the top of the hopper and withdrawn from an outlet at the bottom of the hopper, the pressure at the hopper outlet due to the weight of the material in a comparatively full hopper bin may cause difficulties either in opening and closing an outlet control or difficulties with schemes for removing the material from that outlet location. An example of this last problem would be undue pressure exerted on a conveyor system at the outlet of a hopper bin. Such pressure may result in a grinding of material, and for example, with pelletized feeds, undesirable variations in the composition of the material being dispensed.
Inserts for hopper bins have been suggested, however, typically such inserts form the bin outlet valving arrangement as, for example, illustrated in U.S. Pat. Nos. 1,147,325; 1,736,673; 3,556,469; and 4,410,111. In this last mentioned patent, a conical member is suspended from the roof of the bin by three cables connected to the cone pinnacle while the circular base of the cone selectively engages the portion of the bin tapering toward the bin outlet to form a valve closing the bin outlet. Shortening the suspension cables raises the cone allowing an annular flow of material around the cone base and out the hopper outlet. With this hollow conical valving device, material flow remains uneven around the entire circumference of the valve base edge due to the unit's ability to move substantially, off center, thus entrapping material against the nearest side.
Among the several objects of the present invention may be noted the provision of a flow enhancement device for suspension within a hopper bin which remains at a fixed elevation above the bin outlet regardless of whether material is being drained from the bin or not; the provision of a geometrical shape having limited angular and swinging mobility during material flow from a storage bin for reducing flow irregularities when material is allowed to drain from the bottom of such a bin; the provision of a scheme for introducing a device into a material flow path which device initiates numerous small avalanches of material so as to avoid a material build up which could result in a much larger avalanche of that material; the provision of a hollow flow enhancing device capable of selectively receiving ballast material to tailor the device to a particular material flow environment; and the provision of a material agitating device which may be suspended within a storage bin for reducing irregularities in material eminating from that bin. These as well as other objects and advantageous features of the present invention will be in part apparent and in part pointed out hereinafter.
In general, a flow enhancement device has a diverging upper portion for diverting downwardly moving material incident thereon radially outwardly as that material continues its downward motion along with a lower portion including generally vertical side walls past which the moving material may freely fall. The lower portion side walls need only be more vertically inclined than the diverging upper portion to create a low pressure shearing region through which the material may fall.
Also in general and in one form of the invention, a flow enhancement device to be suspended within a hopper bin near the bottom of the bin at a selected elevation above a bin outlet includes an upper frusto conical portion, a lower generally cylindrical portion and a plurality of flow deflecting fins extending outwardly from the cylindrical portion. Said fins offer two unique advantages: (1) to eliminate material entrapment against a sidewall (2) to cause rotational movement of device. The device may be formed as a one piece hollow geometrical shape of plastic or metal and may include a closable opening near an upper extremity for the optional addition of ballast to the device hollow interior. A loop may be formed integrally with the device near the upper extremity of the upper portion for receiving device suspending lines.